This invention relates to an improved squeeze film damper seal ring and more particularly to a damper seal ring which regulates the flow of oil through a squeeze film damper.
One typical squeeze film damper comprises a rolling element bearing supporting a rotating shaft in a bearing housing of high speed rotary or turbo machinery including hot gas turbine engines such as aircraft gas turbine engines. A bearing support member, for example, the annular race of a rolling element bearing is slidingly fitted in an annular chamber in the bearing housing for limited radial motion therein. The annular race in the annular chamber defines a thin annular squeeze film space between adjacent inner and outer circumferential surfaces of the chamber and race respectively, and a damper fluid such as an oil under pressure is introduced into the squeeze film space to provide a damping action on radial motion of the race and shaft. The annular squeeze film space is sealed by means of a spaced apart pair of gap piston ring seals fitted in grooves in the race and engaging the opposite circumferential wall of the annular chamber. Damper oil from the squeeze film space which passes by the rings in controlled amounts is collected in an appropriate sump and treated, usually cooled if necessary, and recirculated through the damper. Controlled oil flow through or past the rings is an important operating factor in squeeze film dampers. High pressure, high velocity damper fluid flow through small ring spaces into a low pressure ambient region external to the damper results in disruption of the oil film in the squeeze film space, together with air entrainment in the squeeze film with a concurrent loss of damper effectiveness.